<!DOCTYPE html>
<p>There should be a hotpink square, centered inside a yellow rectangle.</p>
<div style="columns:3; column-gap:0; column-fill:auto; padding:10px; height:6em; margin-top:100px; width:18em; background:yellow;">
    <div style="height:6em;"></div>
    <div style="width:6em; height:3em; background:hotpink;"></div>
    <div style="position:absolute; width:6em; height:3em; background:hotpink;"></div>
</div>
